1. Field of the Invention
This invention concerns endless woven bands of tubular fabrics which are used as a carcass for power transmission and conveyor belts and dryer felts. In particular, the field of invention relates to a fabric which is in tubular form and has a longitudinal warp weave and a transverse weft weave which are the same configuration.
2. Description of the Prior Art
The prior art discloses many types of woven fabrics. In U.S. Pat. No. 200,965, Baker discloses a fabric wherein, in the case of a three-ply fabric, one-half of the warps of the inner and outer plys passes alternatively over and under the weft in nearly a straight line, while the remaining portion of the warps of the outer and inner plys passes diagonally around the central lines of the weft, and is thus used to form an intermediate ply. In the case of a four-ply fabric, Baker teaches that one-half of the warps of the inner and outer plys is arranged as the three-ply fabric, while the remaining portion of the warps of the outer and inner plys passes respectively around that line of weft which is adjacent to the outer and inner ply, and is thus used to form intermediate plys which are locked together by a separate series of warps which pass diagonally from one to the other of said intermediate plys.
In U.S. Pat. No. 1,994,280, issued to Hindle, dryer felts for use on paper making machines are disclosed. Therein is described a two-ply fabric in which the weave is composed of eight warp threads and two layers of weft threads, three of the warps being woven in to form one layer with each pick of one weft thread, three of the warps being woven in to form the second layer with each pick of the second weft thread and two warps being woven in each alternative pick by both weft threads to bond the two layers together whereby all the eight warp threads are the same length and under the same tension in the felt. This results in a fabric composed of two layers of weft threads and eight coarse warp threads, three of the warps forming the top layer, three of the warps forming the bottom layer and two warps serving to bind the two layers together and also to complete the top and bottom faces of the fabric, the two binding warps being woven by the weft threads on each alternative pick.
Hindle, et al. discloses additional types of paper makers' dryer felts in U.S. Pat. No. 2,934,097. In particular, Example 2 shows a two-layer structure having weft and warp ends interwoven so as to appear on both the face and back of the felt, the surface warp yarns being arranged in one-third broken twill order. In addition, Example 4 teaches a two-layer felt having weft layers and warp layers which appear on both the face and back of the fabric and are arranged in a 6-end satin order. The fabric disclosed by Hindle, et al. is of symmetrical construction such that the crossing points of adjacent warps are always equidistant from successive wefts of the face layer, while successive wefts of the face layer are always directly above successive wefts of the back layer.
Watts, et al., in U.S. Pat. No. 2,866,483, teaches a reinforced power transmission and conveyor belt made of woven textile materials. A three-ply textile fabric is shown which consists of alternating sections in which weft threads are disposed across the width of the strip and warp threads are disposed parallel to the length of the strip.
In British Pat. No. 1,220,531, Aktiebolaget teaches a machine cloth for paper making, the main feature of which is the weft layer of the cloth being directed toward the material to be dewatered.
Basically, the prior art differs from the invention disclosed herein which includes a longitudinal warp weave which has the same configuration as a transverse weft weave.
The disclosed weave structure provides a tubular fabric which has a reduced cost and increases the quality of rubber impregnated, endless high speed belts. The belts are made from the tubular fabric or sleeve by cutting from a continuously woven piece of tubing, impregnating the cut piece with resins and rubbers, and vulcanizing the impregnated, cut piece. The vulcanized sleeve is then slit to a desired width.
In the prior art, two separate pieces of woven tubing were used, in order to obtain the desired strength, one piece slid over the other piece. After the separate pieces were finally vulcanized, a cloth wrapper was used on the outside to give the desired surface finish.